Production of textile materials



Patented June 21, 1938 am it PATENT orrlce 2,121,040 PRODUCTION OF TEXTILE MATERIALS Robert Wighton Moncrieff and Charles William North, Spondon, near Derby, England, assignors to Celanese Corporation of America, a corporation of Delaware No Drawing. Application April 9, 1935, Serial No. 15,424. In Great Britain May 2, 1934 16 Claims. (01. 8-20) This invention relates to the production of textile materials and particularly to the production of filaments, yarns, ribbons and similar products having a cross-section which varies along their length and to fabrics and other materials-containing such products.

It has beendiscovered that by stretching filaments, yarns, ribbons and similar materials, (hereinafter referred to generically as yarns") 10 which contain cellulose acetate or other ester of cellulose and which hav: been non-uniformly saponified and non-uniformly softened along their length, products may be obtained which have a varying cross-section along their length, and

from which fabrics and other materials showing novel effects may be produced. The cross-section of the artificial materials obtained may vary in either a regular or an irregular manner, that is to say, either so that the portions of different cross-section are repeated in a regular manner along the length of the materials, or so that they occur in an arbitrary manner.

According to the process of the present invention many varied and novel effects may be obtained. Thus, by subjecting filaments, yarns,

ribbons and similar materials to a saponifying treatment in such a manner that portions of the materials are substantially or completely saponified while other portions are unsaponified, and then softening the materials with suitable softening agents for the cellulose ester contained in the materials and stretching them, the unsaponified portions may be stretched to a considerable extent, for example 300, 400 or 500% or even more of their original length, while the saponified portions will be substantially unstretched, so that materials which vary considerably in cross -section along their length and which resemble slub yarn may be obtained.

Not only does the present invention render it possible to produce novel effects due to difference in cross-section of the materials along their length, but also the materials may have a differential aflinity for dyestuffs along their length, so that when they are dyed, products showing special colour effects may be obtained. Thus,

65 saponified portions, so that cross-dyed effects amine or other lower aliphatic amine.

may be obtained. Again, shaded effects may be obtained by dyeing materials which have been differentially saponified so that their afiinity for the dyestuff varies gradually along their length and the depth to which they are dyed 5 consequently also varies gradually along their length. Such shaded effects may be produced alongthe whole length of the materials, or may alternate with portions which are undyed or dyed a different colour. afiinity of the yarns for dyestuffs may be produced, for example, by contacting the yarns during their travel from one point to another with a wick 'or roller carrying saponifying agent and varying the pressure of the yarns against 15 the wick or roller so that the amount of saponifying agent taken up varies gradually. Such a process may also produce a gradual alteration in the reaction of the yarn along its length to softening media, so that on treating the yarn with such 20 media and stretching it a product of gradually varying denier is obtained.

While various examples of different effects which may be obtained according to the present invention have been given above, it is evident that 25 these examples are by no means exhaustive, and that, in fact, an almost infinite number of different effects may be obtained by variations in the different factors, for example in the lengths of the portions'of. different degrees of saponification, 30

the regularity or irregularity of the saponification pattern, the abruptness or'otherwise of the variation in the degree of saponification along the length of the yarns, the degree of stretching, the portions of the yarns in which such stretch 35 is produced, and the method of colouring the yarn or fabrics or other materials containing the yarn. saponification of the artificial materials is preferably effected during the course of their travel from one point to another, and processes 40 in which a number of artificial threads or similar materials are saponified when in parallel alignment in the form of a sheet are particularly valuable. The saponification may be effected so that it varies in either a regular or an irregular manner along their length. Examples of suitable processes and apparatus are described in U.\ S. Patent No. 1,992,259, and U. S. Patent No. 2,000,935. The saponifying agent may be inorganic, e. g. caustic soda, caustic potash or sodium silicate, or organic, for example a methyl- Processes for the saponification with organic bases of materials containing organic esters of cellulose are described in U. S. Patents Nos. 2,091,967,

Gradual changes in the 10 stretching operations yarns which are non-uni-' iormly saponifled and are of varying denier along their length may be obtained in a single operation.

The degree of saponification may vary along the length of the materials as desired. Thus,

portions may be slightly saponi'fied, e. g., to the extent of 5 or 10% of their original weight, and the remaining portions saponified to a substantial extent or completely, or portions may be unsaponified and other portions saponifled to any desired extent. As stated above, the degree of saponiiication along the length of the materials may vary relatively abruptly or gradually. Moreover, partial saponiflcation may be superficial only or may be substantially uniform throughout the cross-section of the materials. For this latter purpose organic saponifying agents such as are employed according to the specifications referred to above are particularly valuable, as are also caustic soda in the presence of gelatine, as is described in U. S. Patent No. 2,080,768, and sodium silicate.

The reduction in cross-section may be effected by uniformly treating the non-uniformly saponlfied materials with a softening agent for a part of the yarn and subjecting them to tension so as. to stretch them. On account of the varying constitution of the materials along their length, softening will not be uniform, so that when sub- Jected to tension they will stretch to a varying extent along their length, and products may be obtained having a varying cross-section along their length.

The stretching of the artificial materials is'also preferably efiected during the course of their travel from one point to another, and especially when they are in parallel alignment in sheet formation, as described, for example, in British Patent No. 371,461. Stretching may be effected in a single stage or in two or more stages, as described in British Patent No. 370,430. The degree of stretch may vary considerably according to the difi'erence in cross-section which it is desired to produce between the stretched and unstretched portions, for example it may be 200, 400, 600% or even more. By stretching in the presence of softening agents for the cellulose ester materials which have been substantially completely saponifled in certain portions, the saponified portions will not, in general, be stretched to any substantial extent. 011 the other hand, materials which still contain proportions of ester groups even in the most saponifledportions may be subjected to a softening treatment, so that they may be stretched all along their length but to difierent degrees and products may be obtained which not only exhibit effects due to difference in crosssection and in afllnity for dyestuffs, but which also have an increased tenacity. Examples of suitable softening agents for facilitating the stretching of materials containing cellulose acetate, to which the present invention is particularly applicable, are acetone, dioxane, ethylene methylene ether, diacetone alcohol, glycol-monoacetate, methyl glycol-mono-acetate, glycol mono-methyl ether, ethyl lactate and ethyl acetate.

The saponification and stretching processes may be carried out in a continuous operation, or materials which have been previously saponified may be stretched according to the present invention in a separate operation.

The following examples are given in order to illustrate the invention, but do not limit it in any way:

Example 1 A cellulose acetate yarn of 200 denier is treated intermittently with a 25% solution of caustic soda while being wound from one bobbin to another, the treated and untreated portions having substantially the same lengths. The yarn is then dried to complete the saponiflcation process. It is then washed to free it from sodium acetate and any unchanged caustic soda and is dried again. In this manner a yarn having unsaponified portions of about 200 denier and saponified portions of considerably lower denier is obtained. It is then passed through a bath containing a 50% aqueous solution of dioxane where it is stretched to 300% of its original length, and then washed, dried and re-wound. The saponifled portion of the yarn is substantially unaffected by the stretching process, while the unsaponified portion is stretched to about 500% of its original length and has a denier of about 40. In this manner a yarn is produced consisting of lengths of unsaponified yarn of about 40 denier alternating with lengths of saponifled yarn of considerably greater denier. The yarn may be then dyed with a cotton or cellulose acetate dyestufl giving a slub yarn having alternating coloured and uncoloured portions, or with a mixture of cotton and cellulose acetate dyestuffs so that a twocoloured yarn is obtained.

Instead of carrying out the saponifying and stretching processes separately, the two processes may be effected in a continuous operation.

Example 2 A celluloseacetate yarn'may be non-uniformly saponified in hank form by dipping portions of the hank into a solution containing 4% of caustic soda and 10% of sodium acetate at 30 C. for about 30 seconds and washing the hank immediately. 'I'he hank may then be dried, wound on to a bobbin and stretched as in the preceding example.

Example 3 A non-uniformly saponified cellulose acetate yarn may be obtained by coating portions of the yarn with an alkali-resisting wax and then passing it through a 25% solution of caustic soda during the transfer of the yarn from one bobbin to another or by dipping it in bank form into a solution of caustic soda such as is employed in Example 2. The yarn may then be stretched as described in Example 1.

Instead of the stretching bath consisting of 50% of aqueous dioxane described in Example 1, any of the following stretching baths may be employed:

A bath consisting of a 52 to 53% aqueoussolution of acetone.

A bath consisting of of ethyl acetate and 10% of toluene. v I

A bath consisting ofa 75% aqueous solution of glycol mono-methyl ether.

A bath consisting of a 50% aqueous solution of ethyl lactate. 1

The percentages of the constituents ofthe stretching baths given above are by volume in each case. i

The differentially saponified and stretched products obtained according to the present invention may be associated together by weaving, knitting, netting or other processes to form fabrics and other materials, and they may be employed either alone or in conjunction with other natural or artificial materials, for example wool, silk, cotton and regenerated cellulose materials and materials containing organic derivatives of cellulose which have uniform properties along their length. For example, a fabric may be produced in which the warp consists of the special yarn obtained according to the present invention and the weft consists of regenerated cellulose materials or ordinary cellulose acetate materials, and it'may then be dyed in order to give a fabric showing colour effects.

While the invention is of particular value in connection with artificial products containing cellulose acetate, it may also be employed in the production of artificial products containing other esters of cellulose, for example cellulose proprionate, butyrate, nitro-acetate and acetatepropionate.

Moreover, while, in general, it is preferable that stretching be effected in the presence of a softening agent for the organic ester of cellulose so that the most saponified portions of the product will have the largest cross-section, yet by the use of suitable softening agents products may be obtained in which the most saponified portions "are most stretched and thus have the smallest cross-section. For example, a cellulose ester yarn, portions of which have been substantially completely saponified, may be treated with a solution of zinc chloride and stretched. In this case the saponified portions of the yarn will have a lower denier than the unsaponified portions.

If desired, the materials, after differential saponification and stretching, may be subjected to further saponification so as to remove partially or completely the remaining ester content. By this means a variable denier product of substantially uniform chemical constitution may be produced. A nitrocellulose thread or a thread of a saponifiable organic ester of cellulose may be used as the starting material for such a process.

Furthermore, a thread which has been saponified at intervals along its length. may be subjected to a process which simultaneously stretches and saponifies the portions of the thread still containing ester groups. Methylamines, ethylene diamine and similar bases which permit stretching during saponificatlon may be used for this purpose.

What we claim and desire to secure by Letters Patent 152- 1. Process for the production of improved artificial materials, which comprises treating a yarn, filament, ribbon or like material, having a basis of organic ester of cellulose and which is nonuniformly saponified so that differences of acidyl content occur along its length, with a medium adapted to soften portions of the material of differentacidyl content to different extents, and stretching the material in contact with said medium, whereby the portions of the materials softened to different extents are stretched to different extents.

2. Process for the production of improved artificial materials, which comprises treating a yarn,

filament, ribbon or like material, having abasis of organic ester of cellulose and which is saponified at intervals along its length, with a medium adapted to soften the unsaponified portions of the material to a greater extent than the saponified portions, and stretching the material in contact with said medium, whereby the portions of the materials softened to diiferentextents are stretched to different extents.

. intervals along its length, with a medium adapted to soften the unsaponified portions of thematerial to a greater extent than the saponified portions, and stretching the material in contact with said medium, whereby the portions of the materials softened to different extents are stretched to different extents.

4. Process for the production of improved artificial materials, which comprises treating a yarn, filament, ribbon or like material, having a basis of organic ester of cellulose and which is saponified at intervals along its length, with a medium comprising an organic liquid adapted to soften the unsaponified portions of the material to a greater extent than the saponified portions, and stretching the material in contact with said medium, whereby the portions of the materials softened to different extents are stretched to different extents.

5.. Process for the production of improved artificial materials, which comprises treating a yarn, filament, ribbon or like material, having a basis of organic ester of cellulose and which is saponified at intervals along its length, with a medium containing an organic base adapted to soften the unsaponified portions of the material to a greater extent than the saponified portions and simultaneously to efiect further saponification, and stretching the material in contact with said medium, whereby the portions ,of the materials softened to different extents are stretched to different extents.

6. Process for the production of improved artificial materials, which comprises intermittently saponifying a yarn, filament, ribbon or like material having a basis of organic ester of cellulose by treating said material at intervals along its length with a saponifying agent, treating the intermittently saponified material so produced with a medium adapted to soften the unsaponified portions of the material to a greater extent than the saponified portions, and stretching the material in contact with said medium, whereby the portions of thematerials softened to different extents are stretched to different extents.

'7. Process for the production of improved.artificial materials, which comprises treating a yarn, filament, ribbon or like material, having a basis of organic ester of cellulose, at intervals along its length with a medium containing an organic base so that the material is saponified and softened at the points where the medium is applied, and subjecting the softened material so produced to a stretching operation, so that substantially only the saponified portions are stretched.

8. Process for the production of improved artificial materials, which comprises treating a yarn, filament, ribbon or like material, having a basis of cellulose acetate, at intervals along produced to a stretching operation, so that substantially only the saponified stretched.

9. Process for the production of improved artificial materials, which comprises treating a yarn, filament, ribbon or like material having a basis of organic ester of cellulose and having along its length substantially completely saponifled portions alternating with unsaponifled portions, with a medium adapted to soften the unportions are saponified portions of the material but not the substantially completely saponified portions, and stretching the material in contact with said medium, whereby the portions of the materials softened to different extents are stretched to different extents.

10. Process for the production of improved artificial materials, which comprises treating ayarn, filament, ribbon or like material having a basis of cellulose acetate and which is saponifled at intervals along its length, with a medium adapted to soften the unsaponified portions of the material to a greater extent than the saponified portions, stretching the material in contact with said medium whereby the portions of the materials softened to different extents are stretched to different extents, and then saponifying the product until all the acetate groups have been removed.

11. Process for the production of improved artificial materials, which comprises treating a yarn, filament, ribbon or like material, having abasis of cellulose acetate, at intervals along its length with a medium containing an organic base so that the material is saponified and softened at the points where the medium is applied, subjecting the softened material so produced to a stretching operation so that substantially only the saponified portions are stretched and then saponifying the product until all the acetate groups have been removed.

, 12. Process for the production of improved artificial materials, which comprises treating a yarn, filament, ribbon or like material having a basis of cellulose acetate and which is saponifled at intervals along its length, with an aqueous solution of dioxane adapted to soften the unsaponified portions of the material to a greater extent than the saponified portions, and stretching the material in contact with said solution of dioxane, whereby the portions 01' the materials softened to diflerent extents are stretched to different extents.

13. Process for the production. of improved artificial materials, which comprises treating a yarn, filament, ribbon orlike material having a basis of cellulose acetate and which is saponified at intervals along its length, with an aqueous solution of acetone adapted to soften the unsaponified portions of the material to a greater extent than the saponified portions, and stretching the material in contact with said solution of acetone, whereby the portions of the matea rials softened to diflerent extents are stretched to different extents.

14. Process for the production of improved artificial materials, which comprises treating a yarn, filament, ribbon or like material having a basis of cellulose acetate and which is saponified at intervals along its length with an aqueous solution of diacetone alcohol adapted to soften the unsaponified portions of the material to'a greater extent than the saponified portions, and stretching the material in contact with said solution of diacetone alcohol, whereby the por tions of the materials softened to diflerent extents are stretched to different extents.

15. Yarns, filaments, ribbons and like materials having -a basis of organic ester of cellulose and having along their length portions which differ from other portions in acidyl value, in degree of stretch and in cross-sectional area.

16. Yarns, filaments, ribbons and like materials having a basis of cellulose acetate and having along their length portions which dliTer from other portions in acetyl value, in degree of stretch and in cross-sectional area.

ROBERT WIGHTON Monomers; enemies tern hearts. 

